The Neurovirology (NV) Core is a new addition to the HNRC whose overall objective is to support, through national and international collaboration and capacity-building, efforts at the identification and characterization of HIV genotypes and phenotypes associated with initiation, maintenance, and progression of neuroAIDS. Our scientific and service aims are to (1) identify the genotype of neuroadaptive HIV at varying stages of HIV-associated neurological disease;(2) to determine the phenotype of this neuroadaptive genotype;and (3) to develop methods for investigating viral dynamics and evolution within the CNS. Since viral populations in the CNS can be genetically distinct from populations in other tissues, such as blood, lymphoid and genital tract, appropriate virologic techniques will be needed to characterize neurotropism and neurovirulence in the CNS. This Core will enhance the HNRC's transdiciplinary aims through close collaboration with the Neurobehavioral, Neuromedical and Neurobiology Cores, utilizing multiple virologic techniques specific to CNS derived virus and its analysis. Considerable amounts of virologic data, specifically sequence data, will be generated through the objectives of this Core, including international collaborations. Management of these data will be aided through a web-based system, developed in cooperation with the Data Management and Information Systems Core. Investigating the impact of HIV-associated neurological disease throughout the world will require the development of location specific virologic capabilities. Through existing (e.g., Brazil, India, and China) and planned (e.g., Romania, South Africa) collaborations, we will provide technical support in the development of molecular virology capabilities to address the specific research objectives of each locale. The Neurovirology Core, with its ability to characterize HIV genetics, is essential to fundamental advances in understanding the neuropathogenesis of neuroAIDS.